Inorganic-organic plastic

ABSTRACT

An inorganic-organic plastic having improved strength, elasticity, dimensional stability with increase in temperature and flame resistace and adapted for use in filling cracks and cavities and for making materials useful in the building industry is prepared by (1) premixing (c) an organic compound having at least two reactive hydrogen and at least one non-ionic hydrophilic group with (b) an aqueous silicate and then mixing the resulting mixture with (a) an organic polyisocyanate or (2) mixing (a), (b) and (c) simultaneously and reacting the mixture thus obtained to form a colloidal xerosol.

This is a divisional of our copending application Ser. No. 527,386,filed Nov. 26, 1974, now U.S. Pat. No. 4,042,536.

It is known that polyurethane plastics and polyurea plastics can beproduced from organic polyisocyanates and compounds which contain activehydrogen atoms. The properties of this class of polymers can be widelyvaried. The high strength, elasticity and wear resistance are consideredto be particularly valuable properties of these products but theirthermo-stability and particularly their dimensional stability attemperatures above 120° C. is only moderate. The use of such products asbuilding and constructional elements is limited by their poor firecharacteristics. Although these can be improved by means offlame-retarding agents, these agents in most cases have an adverseeffect on the mechanical properties.

It is also known to produce inorganic silica gel plastics by the actionof acids or anhydrides on aqueous solutions of alkali metal silicates.These plastics have become important particularly as putties and surfacecoatings. Light-weight foam plastics have also been produced from waterglass. The products have a high dimensional stability when heated andare completely incombustible, but they are brittle and have relativelylittle strength. As foams, they have little ability to withstand loadsand crumble when under pressure. It would be extremely desirable tocombine the advantageous properties of inorganic and organic plasticsmaterials and suppress the undesirable properties of both.

There has therefore been no lack of attempts to produce combinationplastics, but the desired aim has so far not been achieved.

Thus for example polyurethanes have been mixed with active silica asfiller and then vulcanized. A certain reinforcing effect can then beobserved similar to that obtained when using very active carbon black,that is to say the tensile strength and modulus increase but theelongation at break decreases. However, the material is notfundamentally altered in its properties by the addition of silica,presumably because the two components form a two phase system in whichonly the polyurethane forms a coherent phase while the silica isembedded as an incoherent phase in the polyurethane. The incoherentzones have diameters of the order of 3 to 100μ. One is therefore dealingwith relatively coarse heterogeneous two phase systems. The interactionbetween the two phases is only slight, both on account of the relativelysmall interface and on account of the very differing chemical nature ofthe two phases.

It has also been proposed to use silica in a microfibrous form. Thereinforcing effect thereby obtained increases due to the specificmorphology of this form of silica but the incoherent zones inevitablybecome larger so that the chemical interaction between the two phases ifanything decreases. The fundamental character of a coarse heterogeneoustwo phase plastic remains.

It is also known to react an aqueous solution of an alkali metalsilicate with a low-molecular weight polyisocyanate, e.g.4,4'-diphenylmethane diisocyanate. This reaction in most cases resultsin foams in which the isocyanate phase is caused to react by thepresence of water, and the carbon dioxide causes the mass to foam up,part of the carbon dioxide entering into a reaction with the surroundingaqueous silicate phase which results in gelling of the interface.

The reaction is preferably carried out with the quantity of water glasspredominating so that the resulting mixture is an emulsion of theisocyanate in a coherent silicate solution. The resulting foam thereforehas the character of a silicate foam which contains incoherent zones offoamed polyurea. The properties of such a foam do not differsubstantially from those of a pure silicate foam. Foams obtained in thisway are in fact brittle and with little ability to withstand mechanicalstress.

Similar effects are obtained with other isocyanates such as cyclohexylisocyanate, phenyl isocyanate, hexamethylene diisocyanate,diphenylmethane-2,4-diisocyanate and tolylene diisocyanate as well asadducts of these isocyanates with low-molecular weight glycols such asethylene glycol, propylene glycol, butane-1,4-diol, hexane-1,6-diol,neopentyl glycol, glycerol and trimethylolpropane. Although the organiccomponent with isocyanate groups which is added to the silicate solutionacts as hardener, it has little influence on the properties of the foamand frequently affects it adversely. The organic component obviouslyexists mainly as a filler in the finished silicate structure.

A quantitative excess of diisocyanate, on the other hand, results inpolyurea foams in which an incoherent silicate phase is dispersed. Theproperties of these foams are therefore basically those of a polyureafoam which is filled with silica, and the foams accordingly are highlycombustible and extremely brittle.

If this procedure is adopted in practice (DOS No. 1,770,384), it isfound that mixtures of aqueous sodium silicate solutions withdiphenylmethane diisocyanate form only relatively coarse emulsions.Although this disadvantage can to a large extent be overcome by therecommended addition of emulsifiers or foam stabilizers which result inmore finely divided and more stable primary emulsions, the properties asa whole are still unsatisfactory and in particular the combinationplastics obtained have a marked brittleness and little strength. Fromthe results previously obtained, it must be concluded that combinationplastics of silicates and organic materials have no decisive advantageover purely organic or purely inorganic materials.

It is therefore an object of this invention to provide a process formaking inorganic-organic plastics which are devoid of the foregoingdisadvantages. Another object of the invention is to provide a processfor making macroscopically or microscopically homogeneousinorganic-organic plastics. Still another object of the invention is toprovide inorganic-organic plastics prepared from aqueous silicates andorganic polyisocyanates which are substantially homogeneous and haveimproved strength, elasticity, dimensional stability with increase intemperature and flame resistance.

The foregoing objects and others are accomplished in accordance withthis invention, generally speaking, by providing a process whichinvolves (1) premixing (c) an organic compound having at least onereactive hydrogen and at least one ionic group or at least one non-ionichydrophilic group with (b) an aqueous silicate and then mixing theresulting mixture with (a) an organic polyisocyanate or (2) mixing (a),(b) and (c) simultaneously and reacting the mixture thus obtained toform a colloidal xerosol.

A process has now been found by which macroscopically completelyhomogeneous inorganic-organic plastics can be obtained which representsolid/solid xerosols similar to the knownacrylonitrile-butadiene-styrene plastics. The completely novel compositematerials obtainable in this way are extremely high-quality plasticswhich differ advantageously in their properties both from purely organicand from purely inorganic materials. In particular, they aredistinguished by their high strength, elasticity, dimensional stabilityin the heat and flame resistance.

It has surprisingly been found that inorganic-organic plastics with highstrength, elasticity, dimensional stability under heat and flameresistance are obtained when organic polyisocyanates are homogeneouslymixed with aqueous solutions of alkali metal silicates and/or aqueoussilica sols in the presence of an organic compound which contains atleast one hydrogen atom capable of reacting with isocyanate in additionto at least one ionic or nonionic-hydrophilic group, and the resultingsol is left to react to form a xerosol.

It was recognized, however, that although the presence of isocyanategroups is useful for obtaining the excellent properties of the resultingnovel inorganic-organic plastics, it is not essential. Moreover,suitable organic compounds are not restricted to products obtained bythe isocyanate polyaddition process. The essential feature, in fact, wasfound to be the colloidal distribution and mutual interpenetration ofthe two phases, whereby specifically high surface interactions orinterface interactions become possible of the kind which arecharacteristic of xerosols. This colloidal morphology which plays anessential part in determining the properties of the composite materialsaccording to the invention is obtained if in addition to polymers oroligomeric precursors of polymers, organic compounds which containgroups which are reactive with the polymers and/or their oligomericprecursors as well as ionic and/or nonionic-hydrophilic groups are mixedwith the silicate solution.

By using organic compounds having both reactive hydrogens and ionic ornon-ionic hydrophilic groups, such homogeneous distribution of theorganic and aqueous inorganic phases is achieved that sols are formed inwhich the disperse phase has dimensions of between about 20 nm and 2μ,preferably between 50 nm and 700 nm, so that the chemical interactionsincrease by orders of magnitude and novel composite materials areobtained. In particular, it is also possible to produce a colloidalfibrous structure so that the two phases can exist as coherent systems.This means that a macroscopically homogeneous and in many cases even amicroscopically homogeneous composite material is obtained whichcombines the advantages of inorganic and of organic plastics.

This invention therefore provides a process for producinginorganic-organic plastics which have high strength, elasticity,dimensional stability when heated and flame resistance which is acomposite of a polymer and a polysilicic acid gel in the form of acolloidal xerosol wherein

(a) an organic polyisocyanate,

(b) an aqueous silicate solution and/or an aqueous silica sol, and

(c) an organic compound which contains at least one hydrogen atomcapable of reacting with isocyanate and at least one ionic and/ornonionic-hydrophilic group, are mixed and reacted, characterized in thatmixing is carried out either by first preparing a preliminary mixture of(b) and (c) or by mixing (a), (b) and (c) together simultaneously.

The organic compounds (c) used are preferably compounds of the formula

    X -- R -- Y

wherein

X = --OH, --SH, --COOH, --NHR¹

R = C₁ -C₂₀ -alkylene ##STR1##

R¹ = --H, C₁ -C₂₀ -alkyl, ##STR2##

Y = --SO₃ H, --COOH, --SO₃.sup.(-), --OSO₃.sup.(-), --COO.sup.(-), --NR₃¹ (+) --O--(--CH₂ --CH₂ --O--)--_(n) R¹,or, ##STR3## with at least 10%--O--(CH₂ CH₂ --O--)_(n) R¹ blocks,

n = 2-100.

In the process provided by the invention, therefore, novel plastics areproduced from at least three components:

(1) an organic polyisocyanate,

(2) an aqueous solution of an alkali metal silicate and/or an aqueoussilica sol and

(3) an organic compound which contains at least one hydrogen atomcapable of reacting with isocyanate and at least one ionic and/ornonionic-hydrophilic group.

Any suitable organic polyisocyanate may be used as starting component(a) including aliphatic, cycloaliphatic, araliphatic, aromatic orheterocyclic polyisocyanates of the kind described e.g. by W. Siefken inJustus Liebigs Annalen der Chemie, 562, pages 75 to 136, for exampleethylene diisocyanate, tetramethylene-1,4-diisocyanate,hexamethylene-1,6-diisocyanate, dodecane-1,12-diisocyanate,cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate andany mixtures of these isomers,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (DAS No.1,202,785), hexahydrotolylene-2,4- and -2,6-diisocyanate and anymixtures of these isomers, hexahydrophenylene-1,3- and/or-1,4-diisocyanate, perhydrodiphenylmethane-2,4'- and/or4,4'-diisocyanate, phenyl-1,3- and -1,4-diisocyanate, tolylene-2,4- and-2,6-diisocyanate and any mixtures of these isomers, diphenylmethane2,4'- and/or -4,4'-diisocyanate, naphthylene-1,5-diisocyanate,triphenylmethane-4,4',4"-triisocyanate,polyphenyl-polymethylene-polyisocyanates, which can be obtained byaniline-formaldehyde condensation followed by phosgenation and whichhave been described e.g. in British patent specification Nos. 874,430and 848,671, perchlorinated aryl polyisocyanates as described e.g. inU.S. Pat. No. 3,277,138, polyisocyanates which contain carbodiimidegroups as described in U.S. Pat. No. 3,152,162, diisocyanates of thekind described in U.S. Pat. No. 3,492,330, polyisocyanates which containallophanate groups as described e.g. in British patent specification No.994,890, Belgain patent specification No. 761,626 and published Dutchpatent application No. 7,102,524, polyisocyanates which containisocyanurate groups as described e.g. in German patent specificationNos. 1,022,789; 1,222,067 and 1,027,394 and in GermanOffenlegungsschrift Nos. 1,929,034 and 2,004,048, polyisocyanates whichcontain urethane groups as described e.g. in Belgian patentspecification No. 752,261 or in U.S. Pat. No. 3,394,164, polyisocyanateswhich contain acylated urea groups according to U.S. Pat. No. 3,517,039,polyisocyanates which contain biuret groups as described e.g. in U.S.Pat. No. 3,124,605, in British patent specification No. 889,050 and inU.S. patent application Ser. No. 036,500 filed May 11, 1970, nowabandoned polyisocyanates prepared by telomerization reactions asdescribed e.g. in Belgian patent specification No. 723,640,polyisocyanates which contain ester groups of the kind mentioned e.g. inBritish patent specification Nos. 956,474 and 1,072,956, in U.S. Pat.No. 3,567,763 and in German patent specification No. 1,231,688, andreaction products of the above mentioned isocyanates with acetalsaccording to U.S. Pat. No. 3,120,502.

The distillation residues which are obtained from the commercialproduction of isocyanates and which still contain isocyanate groups mayalso be used, if desired dissolved in one or more of the above mentionedpolyisocyanates. Any mixtures of the above mentioned polyisocyanates mayalso be used.

It is generally preferred to use commercially readily availablepolyisocyanates such as tolylene-2,4- and -2,6-diisocyanate and anymixtures of these isomers ("TDI"), polyphenyl-polymethylenepolyisocyanates which are obtained by aniline-formaldehyde condensationfollowed by phosgenation ("crude MDI") and polyisocyanates which containcarbodiimide groups, urethane groups, allophanate groups, isocyanurategroups, urea groups or biuret groups ("modified polyisocyanates").

It is particularly preferred, however, to use polyisocyanates which areobtained by phosgenating aniline-formaldehyde condensates.

Reaction products of about 50 to 99 mols of aromatic diisocyanates withabout 1 to 50 mols of compounds which contain at least two hydrogenatoms capable of reacting with isocyanate and which generally have amolecular weight of about 400 to about 10,000 may also be used.

The organic compounds having reactive hydrogens (component c) areunderstood to be not only compounds which contain amino groups, thiolgroups or carboxyl groups but particularly also polyhydroxyl compoundsand especially those which contain two to eight hydroxyl groups andwhich have a molecular weight of about 800 to about 10,000, preferablyabout 1,000 to about 6,000, e.g. polyesters, polyethers, polythioethers,polyacetals, polycarbonates and polyester amides which contain at least2, generally 2 to 8 and preferably 2 to 4 hydroxyl groups and at leastone ionic or non-ionic hydrophilic group, of the kind which are knownper se for producing both homogeneous and cellular polyurethanes.

Any suitable polyesters with at least one hydroxyl group may be used tomake component (c) including e.g. reaction products of polyhydric,preferably dihydric alcohols with the optional addition of trihydricalcohols, and polybasic, preferably dibasic carboxylic acids. Instead offree polycarboxylic acids, the corresponding polycarboxylic acidanhydrides or corresponding polycarboxylic acid esters of lower alcoholsor their mixtures may be used for producing the polyesters. Thepolycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/orheterocyclic and may be substituted, e.g. with halogen atoms, and/orunsaturated. The following are examples: succinic acid, adipic acid,suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalicacid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acidanhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acidanhydride, endomethylene tetrahydrophthalic acid anhydride, glutaricacid anhydride, maleic acid, maleic acid anhydride, fumaric acid,dimeric and trimeric fatty acids such as oleic acid, optionally mixedwith monomeric fatty acids, dimethyl terephthalate and bis-glycolterephthalate. Suitable polyhydric alcohols include e.g. ethyleneglycol, propylene-1,2- and -1,3-glycol, butylene-1,4- and 2,3-glycol,hexane-1,6-diol, octane-1,8-diol, neopentyl glycol, cyclohexanedimethanol (1,4-bis-hydroxymethyl cyclohexane),2-methyl-1,3-propanediol, glycerol, trimethylolpropane,hexane-1,2,6-triol, butane-1,2,4-triol, trimethylolethane,pentaerythritol, quinitol, mannitol and sorbitol, methyl glycoside,diethylene glycol, triethylene glycol, tetraethylene glycol,polyethylene glycols, dipropylene glycol, polypropylene glycols,dibutylene glycol and polybutylene glycols. The polyesters may alsocontain a proportion of carboxyl groups in end positions. Polyesters oflactones such as ε-caprolactone or hydroxycarboxylic acids such asω-hydroxycaproic acid may also be used.

Any suitable hydroxyl polyether with at least one, generally two toeight and preferably two to three hydroxyl groups which may be used tomake component (c) according to the invention are also known per se andmay be prepared e.g. by polymerizing epoxides such as ethylene oxide,propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide orepichlorohydrin, each with itself, e.g. in the presence of BF₃, or byaddition of these epoxides, optionally as mixtures or successively, tostarting components which contain reactive hydrogen atoms such asalcohols or amines, e.g. water, ethylene glycol, propylene glycol-(1,3)or -(1,2), trimethylolpropane, 4,4'-dihydroxy-diphenylpropane, aniline,ammonia, ethanolamine, or ethylene diamine. Sucrose polyethers such asthose described e.g. in German Auslegeschrift Nos. 1,176,358 and1,064,938 may also be used according to the invention. It is frequentlypreferred to use polyethers which contain predominantly primaryOH-groups (up to 90% by weight, based on all the OH-groups in thepolyether). Polyethers modified with vinyl polymers of the kind whichcan be obtained e.g. by polymerizing styrene or acrylonitrile in thepresence of polyethers (U.S. Pat. Nos. 3,383,351; 3,304,273; 3,523,093and 3,110,695 and German patent specification No. 1,152,536), andpolybutadienes which contain OH-groups are also suitable.

Suitable polythioethers are in particular the condensation products ofthiodiglycol with itself and/or with other glycols, dicarboxylic acids,formaldehyde, aminocarboxylic acids or amino alcohols. The productsobtained are polythio mixed ethers, polythioether esters orpolythioether ester amides, depending on the co-component.

Suitable polyacetals are e.g. the compounds which can be prepared fromglycols such as diethylene glycol, triethylene glycol,4,4'-dioxethoxy-diphenyl dimethylmethane, hexanediol and formaldehyde.Polyacetals suitable for the invention may also be prepared bypolymerizing cyclic acetals.

Suitable polycarbonates with hydroxyl groups are of the kind known perse which can be obtained e.g. by reacting diols such aspropane-1,3-diol, butane-1,4-diol and/or hexane-1,6-diol or diethyleneglycol, triethylene glycol or tetraethylene glycol with diarylcarbonates such as diphenyl carbonate or phosgene.

The polyester amides and polyamides also include the predominantlylinear condensates obtained from polyvalent saturated and unsaturatedcarboxylic acids or their anhydrides and polyvalent saturated andunsaturated amino alcohols, diamines, polyamines and mixtures thereof.

Polyhydroxyl compounds which already contain urethane or urea groups mayalso be used, as well as modified or unmodified natural polyols such ascastor oil, carbohydrates or starch. Addition products of alkyleneoxides to phenol-formaldehyde resins or to urea-formaldehyde resins mayalso be used according to the invention.

Representatives of these compounds which may be used according to theinvention have been described e.g. in High Polymers, Volume XVI,"Polyurethanes, Chemistry and Technology" published by Saunders-Frisch,Interscience Publishers, New York, London, Volume I, 1962, pages 32-42and pages 44-54 and Volume II, 1964, pages 5-6 and 198-199 and inKunststoff-Handbuch Volume VII, Vieweg-Hochtlen, Carl-Hanser-Verlag,Munich 1966, e.g. on pages 45 to 71.

The prepolymers frequently have a viscosity of more than 2000 cP andoccasionally up to 100,000 cP at 25° C.

In cases where such high viscosities are a disadvantage for working theproduct, the viscosity may be reduced by adding low-viscosityisocyanates or by adding inert solvents.

According to the invention, the aqueous solutions of silicates referredto are the solutions of sodium silicate and/or potassium silicate inwater which are normally known as water glass. Crude commercialsolutions which in addition contain substances such as calcium silicate,magnesium silicate, borates and aluminates may also be used. Theproportion of Me₂ O to SiO₂ is not critical and may vary within theusual limits but is preferably 4:0.2. If the water content of theplastics obtained by the reaction with the organic components is ofminor importance, either because it has no undesirable effects orbecause it can easily be removed by drying, than a neutral sodiumsilicate may well be used, which can be prepared in the form of 25-35%solutions. It is preferred, however, to use 32-54% silicate solutions,and these can only be obtained at a viscosity below 500 poises, as isnecessary for problem-free working with the solutions, if they aresufficiently alkaline. Ammonium silicate solutions may also be used butare less advantageous. The solutions may be true solutions or colloidalsolutions.

Silica sols which may have an alkaline or acid pH may also be used; theyshould have solids contents of 20-50%. Silica sols are generally used incombination with aqueous silicate solutions.

The choice of concentration depends mainly on the desired end product.Compact materials or materials with closed cells are preferably producedwith concentrated silicate solutions which if necessary are adjusted toa lower viscosity by the addition of alkali metal hydroxide. Solutionswith concentrations of 40-70% by weight can be prepared in this way. Onthe other hand, to produce open-celled light-weight foams, it ispreferred to use silicate solutions with concentrations of 20-45% byweight in order to obtain low viscosities, sufficiently long reactiontimes and low unit weights. Silicate solutions with concentrations of20-45% are also preferred when substantial quantities of finely dividedinorganic fillers are used.

The organic compounds (component c) used according to the inventionwhich contain at least one hydrogen atom capable of reacting withisocyanate as well as at least one ionic and/or non-ionic-hydrophilicgroup are compounds of the kind which are used for example for preparingionic and/or nonionic polyurethane dispersions. In addition, one mayalso use compounds of the kind which merely contain an ionic and/ornonionic-hydrophilic center at any point in the molecule. Such a centerincreases the compatibility of a compound with water compared with thatof a comparable product which does not contain the ionic and/orhydrophilic center.

By reactive groups which are capable of reacting with isocyanate in apolyaddition reaction are meant, apart from amino groups, thiol groupsor carboxyl groups, preferably hydroxyl groups of the kind which areknown per se as part of organic compounds for the production ofhomogeneous and of cellular polyurethanes.

The following groups are given as specific examples of suitable ionicgroups. ##STR4## R = C₁ -C₁₂ -alkyl, C₅ -C₁₀ -cycloalkyl, C₆ -C₁₀ -aryl.

The term ionic groups as used here refers not only to the abovementioned preformed salt groups but also to groups which are capable offorming salt groups in the presence of alkali metal silicate, e.g.

--COOH, --SO₃ H, --SO₂ --NH--SO₂ --, --CO--NH--CO-- and phenolicOH-groups.

The organic compound used may, of course, contain several of the abovementioned groups. Betaines which contain an anionic group and a cationicgroup in one and the same molecule or symplexes which contain bothanionic and cationic compounds may also be used.

Among the ion-forming groups, the following are particularly preferred:##STR5##

Of these groups, the tert. amino group must be converted into aquaternary ammonium group before it is combined with the alkali metalsilicate solution. This can be achieved by means of alkylating agentsbut also with the aid of inorganic or organic acids.

The following are given as examples of suitable compounds which containboth at least one hydrogen atom capable of reacting with isocyanate andat least one ionic group:

(1) Reaction products of

(a) compounds which contain at least one basic nitrogen atom and atleast one hydrogen atom capable of reacting with isocyanate and

(b) alkylating agents.

The following are examples of suitable compounds which contain at leastone basic nitrogen atom and at least one hydrogen atom capable ofreacting with isocyanate: mono-, bis- and polyoxalkylated aliphatic,cycloaliphatic, aromatic and heterocyclic primary amines such asN-methyl-diethanolamine, N-ethyl-diethanolamine,N-propyl-diethanolamine, N-isopropyldiethanolamine,N-butyl-diethanolamine, N-isobutyl-diethanolamine,N-oleyl-diethanolamine, N-stearyl-diethanolamine, oxethylated coconutfatty amines, N-allyl-diethanolamine, N-methyl-diisopropanolamine,N-ethyl-diisopropanolamine, N-propyl-diisopropanolamine,N-butyl-diisopropanolamine, N-cyclohexyl-diisopropanolamine,N,N-dioxethyl aniline, N,N-dioxethyl-toluidine,N,N-dioxethyl-α-aminopyridine, N,N'-dioxethyl-piperazine,dimethyl-bis-oxethyl hydrazine,N,N'-bis-(β-hydroxy-ethyl)-N,N'-diethyl-hexahydro-p-phenylene diamine,N-β-hydroxyethyl piperazine, polyalkoxylated amines such as propoxylatedmethyl-diethanolamine; compounds such asN-methyl-N,N-bis-γ-aminopropylamine,N-(γ-aminopropyl)-N,N'-dimethylethylene diamine,N-(γ-aminopropyl)-N-methyl-ethanolamine,N,N'-bis-(γ-aminopropyl)-N,N'-dimethyl-ethylene diamine,N,N'-bis-(γ-aminopropyl)-piperazine, N-(β-aminoethyl)-piperazine,N,N'-bis-oxethyl-propylene diamine, 2,6-diaminopyridine,diethanolamino-acetamide, diethanolamino propionamide,N,N-bis-oxethyl-phenyl-thiosemicarbazide,N,N-bis-oxethyl-methylsemicarbazide, p,p'-bis-aminomethyl-dibenzylmethylamine, 2,6-diamino-pyridine and the like.

Compounds which contain halogen atoms capable of being quaternized orR--SO₂ O-groups include, for example, glycerol-α-chlorohydrin, glycerolmonotosylate, pentaerythritol-bis-benzene sulphate, glycerol-monomethanesulphonate, adducts of diethanolamine and chloromethylated aromaticisocyanates or aliphatic halogenated isocyanates such asN,N-bis-hydroxyethyl-N'-m-chloromethyl-phenyl-urea,N-hydroxyethyl-N'-chlorohexyl urea, glycerol-monochloroethyl-urethane,bromoacetyldipropylene triamine, chloroacetic acid diethanolamide andthe like.

Trifunctional or higher functional components such as triethanolamine,diethylene triamine or dipropylene triamine may be used. Branchedpolyesters or polyethers which contain basic nitrogen may also be used,provided they contain hydrogen atoms which are reactive with isocyanate.

Monofunctional compounds which contain only one group which is reactivewith isocyanates may also be included, e.g. saturated or unsaturatedfatty alcohols, fatty amines or fatty acids, resinic acids,N,N-dimethyl-ethanolamine, N,N-diethyl-ethanolamine,1-dimethylaminopropanol-(2), N-oxethylmorpholine,N-methyl-N-β-hydroxyethyl aniline, N-oxethylpiperidine,α-hydroxyethyl-pyridine, γ-hydroxyethyl-quinoline, N,N-dimethylhydrazine, N,N-dimethyl-ethylene diamine, 1-diethylamino-4-aminopentane,α-aminopyridine, 3-amino-N-ethyl carbazol,N,N-dimethylpropylene-diamine, N-amino-propyl-piperidine,N-aminopropyl-morpholine, N-aminopropyl-ethylene imine,1,3-bis-piperidino-2-aminopropane and the like.

The following are examples of monofunctional alkylating agents which maybe used for converting the basic reactants into the salt form:

methyl chloride, methyl bromide, methyl iodide, ethyl bromide, propylbromide, butyl bromide, dimethyl sulphate, diethyl sulphate, methylchloromethyl ether, methyl-1,2-dichloroethyl ether, ethyl chloromethylether, benzyl chloride, benzyl bromide, p-chlorobenzyl chloride,trichlorobenzyl chloride, p-nitrobenzyl chloride, ethylene chlorohydrin,ethylene bromohydrin, epichlorohydrin, ethylene oxide, propylene oxide,styrene oxide, benzene-, toluene- and naphthalene-sulphonic acid ester,ω-bromoacetophenone, dinitrochlorobenzene, α-chloropentenamide,chloroacetic acid and its esters and amides,chloromethyl-dimethyl-ethoxysilane, pentamethyl-bromomethyl-disiloxane,glycol monobromoacetic acid ester, glycerol monochloroacetic acid ester,bromoethyl isocyanate, chloromethyl naphthalene,3-methyl-3-hydroxymethyl-oxetan-methane sulphonate, phenyl ethylbromide, p-2-bromoethylbenzoic acid, 5-chloromethyl-furan-2-carboxylicacid, dichloroisopropyl ester of ethyl phosphonous acid, bromoethylester of acetoacetic acid, propane sultone, butane sultone and the like.Further examples may be found in DAS No. 1,205,087.

Quaternization may also be carried out with cyanogen chloride orcyanogen bromide. Epoxides are used as quaternizing agents incombination with water and/or an acid.

Polyfunctional alkylating agents are also suitable e.g.1,4-dibromobutane, p-xylylene-dichloride,1,3-dimethyl-4,6-bis-chloromethyl-benzene,methylene-bis-chloroacetamide, hexamethylene-bis-bromoethyl urethane,adducts of 2-3 mols of chloroacetamide with one mol of di- ortriisocyanate and the like. Further examples of suitable polyfunctionalalkylating agents may be found in Dutch Auslegeschrift No. 67/03743.

Inorganic and organic acids may also be used for salt formation,including those which also have a chain-building function such assulphurous acid, sulphuric acid, hypophosphorous acid, phosphinic acids,phosphonous acids and phosphonic acids, glycolic acid, lactic acid,succinic acid, tartaric acid, oxalic acid, phthalic acid, trimelliticacid and the like. Further examples of acids may be found in GermanPatent Specification No. 1,178,586 and in U.S. Patent No. 3,480,592.Acids such as hydrochloric acid, fluoroboric acid, amidosulphonic acid,phosphoric acid and its derivatives, tartaric acid, oxalic acid, lacticacid, acetic acid, acrylic acid and the like which have the effect ofsubstantially increasing the hydrophilic character of the organiccompounds are particularly preferred. Various salt-binding agents mayalso be used in combination.

The above mentioned compounds which contain reactive hydrogen atoms may,provided they contain basic nitrogen atoms or divalent sulphur atoms, beused in combination with alkylating agents or acids to produce cationicorganic starting compounds.

Cationic starting compounds may accordingly be prepared from compoundswhich contain reactive hydrogen atoms, reactive halogen atoms or estergroups of strong acids in combination with tertiary, secondary orprimary amines, organic sulphides or phosphines.

Anionically modified starting compounds may be similarly used.

Below are given examples of compounds which may be used as startingmaterials which contain at least one hydrogen atom which is reactivewith isocyanate groups and at least one anionic salt group capable offorming anionic salts, these compounds being optionally used asmixtures:

(1) hydroxy acids and mercapto acids such as glyceric acid, glycolicacid, thioglycolic acid, lactic acid, trichlorolactic acid, malic acid,dihydroxymaleic acid, dihydroxyfumaric acid, tartaric acid,dihydroxytartaric acid, mucic acid, saccharic acid, citric acid,aliphatic, cycloaliphatic, aromatic and heterocyclic mono- anddiaminocarboxylic acids such as glycine, α- and β-alanine,6-aminocaproic acid, 4-aminobutyric acid, sarcosine, methionine,leucine, isoleucine, serine, valine, ornithine, histidine, lysine,proline, phenyl alanine, threonine, cysteine, asparagine, glutamine,arginine, aspartic acid, glutamic acid, oxaluric acid, anilidoaceticacid, anthranilic acid, 2-ethylaminobenzoic acid, 3-aminobenzoic acid,4-aminobenzoic acid, N-phenylaminoacetic acid, 3,4-diaminobenzoic acid,5-aminobenzene-dicarboxylic acid and the like;

(2) aminosulphonic acids: amidosulphonic acid, hydroxylaminemonosulphonic acid, hydrazine disulphonic acid, sulphanilic acid,N-phenylamino-methanesulphonic acid, 4,6-dichloroanilinesulphonicacid-(2), phenylene diamine-(1,3)-disulphonic acid-(4,6), N-acetylnaphthylamine-(1)-sulphonic acid-(3), naphthylamine-(1)-sulphonic acid,naphthylamine-(2)-sulphonic acid, naphthylamine disulphonic acid,naphthylamine trisulphonic acid,4,4'-di-(p-aminobenzoyl-amino)-diphenyl-urea-disulphonic acid-(3,3'),taurine, methyl taurine, butyl taurine, 3-aminobenzoicacid-(1)-sulphonic acid-(5), 3-amino-toluene-N-methane-sulphonic acid,6-nitro-1,3-dimethyl benzene-4-sulphamic acid,4,6-diaminobenzene-disulphonic acid, 4,6-diaminobenzene-disulphonicacid-(1,3), 2,4-diaminotoluene-sulphonic acid-(5),4,4'-diaminodiphenyl-disulphonic acid-(2,2'), 2-aminophenol, sulphonicacid-(4), 4,4'-diamino-diphenylether-sulphonic acid-(2),2-aminoanisol-N-methane sulphonic acid, 2-amino-diphenylamine-sulphonicacid, ethylene glycol sulphonic acid, 2,4-diaminobenzene sulphonic acidand the like;

(3) organic phosphorus compounds such as derivatives of phosphinic acid,phosphonous acids, phosphonic acids and phosphoric acids and esters ofphosphorous and phosphoric acid and their thioanalogues, e.g.bis-(α-hydroxyisopropyl)-phosphinic acid, hydroxyalkane phosphonic acid,phosphorous acid bis-glycol ester, phosphorous acid bis-propylene glycolester, phosphoric acid bis-glycol ester, phosphoric acid bis-propyleneglycol ester and the like;

(4) among the hydroxy-, mercapto- and aminocarboxylic acids andsulphonic acids and polycarboxylic acids and sulphonic acids may also beincluded the (optionally saponified) addition products of unsaturatedacids such as acrylic acid or methacrylic acid and unsaturated nitrilessuch as acrylonitrile, addition products of cyclic dicarboxylic acidanhydrides such as maleic, phthalic or succinic acid anhydrides,addition products of sulphocarboxylic acid anhydrides such assulphoacetic or o-sulphobenzoic acid anhydride, addition products oflactones such as β-propiolactone or γ-butyrolactone, addition productsof the reaction products of olefines and sulphur trioxide such as carbylsulphate, addition products of epoxycarboxylic acids and sulphonic acidssuch as glycidic acid or 2,3-epoxy-propanesulphonic acid, additionproducts of sultones such as 1,3-propane sultone, 1,4-butane sultone or1,8-naphthosultone and addition products of disulphonic acid anhydridessuch as benzene disulphonic acid-(1,2)-anhydride with aliphatic andaromatic amines such as 1,2-ethylene diamine, 1,6-hexamethylene diamine,the isomeric phenylene diamines, diethylene triamine, triethylenetriamine, tetraethylene pentamine, pentaethylene hexamine, hydrazines(optionally alkylated), ammonia, amino alcohols such as hydroxyalkylated amines and hydrazines such as ethanolamine, diethanolamine,triethanolamine, ethanol ethylene diamine or ethanol hydrazine, alcoholssuch as ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol,1,6-hexanediol and polyhydric alcohols such as trimethylolpropane,glycerol or hexanetriol; and addition products (optionally hydrogenated)of epoxy compounds and ethylene imine compounds such as ethylene oxide,propylene oxide, butylene oxide, styrene oxide, ethylene imine orunsaturated nitriles such as acrylonitrile with aliphatic and aromaticaminocarboxylic acids and aminosulphonic acids; the reaction products ofhydroxyalkane sulphonic acids, halogenated carboxylic acids orhalogenated sulphonic acids with optionally alkylated hydrazines such ashydrazinoacetic acid, hydrazinoethane sulphonic acid or hydrazinomethanesulphonic acid; the saponified addition products of cyan hydrines withhydrazines such as 1,2-hydrazine-bis-isobutyric acid; and the additionproducts of sodium hydrogen sulphite with olefinically unsaturatedcompounds such as allyl alcohol, maleic acid, maleic acid-bis-ethyleneglycol ester, maleic acid-bis-propylene glycol ester or the like;

(5) hydrazinocarboxylic acids such as hydrazinodicarboxylic acids;

(6) higher-molecular weight condensates such as polyesters which containcarboxyl groups.

The following are examples of suitable compounds for conversion into thesalt form in order to obtain anionic starting compounds:

(1) organic bases such as monofunctional primary, secondary and tertiaryamines, for example methylamine, diethylamine, triethylamine,trimethylamine, dimethylamine, ethylamine, tributylamine, pyridine,aniline, toluidine, alkoxylated amines such as ethanolamine,diethanolamine, triethanolamine, methyl diethanolamine, dimethylaminoethanol or oleyl diethanolamine, and polyfunctional polyamines inwhich the individual amino groups may differ from each other in theirbasicity, for example the polyamines obtained by hydrogenating theaddition products of acrylonitrile and primary or secondary amines, orperalkylated or partially alkylated polyamines such as N,N-dimethylethylene diamine, compounds such as α-aminopyridine, N,N-dimethylhydrazine or the like;

(2) inorganic bases, compounds which are basic in reaction or split offbases, such as ammonia, monovalent metal hydroxides, carbonates andoxides such as sodium hydroxide or potassium hydroxide. Varioussalt-forming agents may also be combined; furthermore, the carboxylgroups may be only partly neutralized.

The anionically modified starting compounds of course need notnecessarily be neutralized. Salt-formation in such cases does not takeplace until the compounds are mixed with the water glass.

Organic starting compounds which contain at least onenonionic-hydrophilic group in addition to at least one hydrogen atomwhich is reactive with isocyanate are also suitable according to theinvention.

The nonionic-hydrophilic groups used are mainly hydrophilic polyethergroups.

Polyether groups which have been synthesized from ethylene oxide andpropylene oxide are preferred.

Particularly suitable starting compounds which contain at least onenonionic-hydrophilic group in addition to a hydrogen atom which isreactive with isocyanate are polyethers which have been obtained fromalcohols with a functionality of 1-3 and ethylene oxide and/or propyleneoxide and which contain OH end groups with at least 10% ethylene oxideblocks.

Polyether compounds or compounds with polyether groups which have beenprepared by different methods may, of course, also be used according tothe invention provided they contain hydrophilic groups.

Monofunctional polyethers based on monohydric alcohols with a molecularweight of about 32 to about 300 and ethylene oxide are quiteparticularly preferred. The ethylene oxide content in the polyethershould preferably be at least 10% by weight. Nonionic-hydrophiliccompounds suitable for the purpose of the invention also includepolycarbonates based on ethylene glycol, propylene glycol ortetraethylene glycol.

Compounds which contain a hydrophilic polyester segment, e.g. oftriethylene glycol or diethylene glycol and succinic acid or oxalic acidare also suitable. These segments may be destroyed in the course of thesubsequent reaction with water glass with the result that the inorganiccomponent hardens and the organic component is rendered hydrophobic.

The hydrophilic center may also be introduced into the organic compoundby incorporating a glycol such as triethylene or tetraethylene glycol.

The hydrophilic group may be contained in the main chain or in the sidechain of the organic compounds.

In addition to the hydrophilic-nonionic segment there may also be anionic center either in the same or in another molecule. The morphologyand interface chemistry of the diphasic plastics according to theinvention can be influenced as desired by using such ionic-nonioniccombinations.

The organic compounds (c) required for the process according to theinvention must cause at least one of the following conditions to befulfilled when they are mixed with the organic polyisocyanate andaqueous silicate solution and/or aqueous silica sol:

(a) formation of finely divided oil-in-water emulsions or

(b) formation of finely divided water-in-oil emulsions.

The organic compound (c) in combination with the polyisocyanate shouldnot be so hydrophilic that the combination is infinitely soluble in theinorganic aqueous phase.

Production of the inorganic-organic plastics according to the inventionis simple to carry out. All that is required is to mix the threestarting components homogeneously, whereupon hardening of the mixture inmost cases takes place immediately. The mixtures are typical finelydivided emulsions or sols. They are not optically clear but in mostcases opaque or milky-white. The xerosol subsequently obtained appearsto be preformed in them. When they are mixed, a prepolymer is formed insitu at least partly by the reaction of the isocyanate component withthe organic component (c). Due to its ionic and/or nonionic-hydrophilicgroups, this prepolymer is capable of forming finely divided emulsionsor sols with the aqueous silicate solution. The reaction of theisocyanate with the isocyanate-reactive hydrogen atom of organiccompound (c) may be catalytically assisted, especially if alkalinesilicate solutions are used.

Mixing of the components may be carried out according to the inventioneither by separately measuring out the three components and mixing themsimultaneously or by mixing silicate component (b) with organic compound(c) and then adding the resulting mixture to the isocyanate component.

In cases where a preliminary mixture of silicate component (b) andorganic compound (c) is first prepared, care must be taken to insurethat the organic compound (c) does not bring about hardening orprecipitation of the silicate component before it is mixed with theisocyanate.

The mixture of all three components is not stable. The so-called potlife during which the mixture remains in a workable state depends mainlyon the chemical nature of the reactive groups of the ionic ornonionic-hydrophilic organic compound (c), on the total quantity ofsilicate hardener liberated and on the concentration of the silicatesolution. It varies from 0.2 seconds to about 15 hours.

A pot life of about 1 second to about 20 minutes is preferred.

It follows that mixing is generally carried out immediately before themolding or shaping process.

It is distinctly surprising that, for example, the reaction between thethree starting components in most cases runs practically to completionwithin a few seconds and no bubbles are formed in the absence ofvolatile compounds. This means that within this short reaction time allthe carbon dioxide liberated by the reaction of the NCO-groups withwater diffuses through the interface into the aqueous phase, therebydemonstrating the extremely large area of the phase interface, which isa major feature of the process according to the invention andcontributes to the surprising properties of the products.

Production of the new composite materials of polymer and silica gel mayin principle be carried out by known technological processes, e.g. thoseemployed for producing cast or foamed polyurethanes. Since, however, thepot life is in most cases short and the reaction often proceedsspontaneously at -20° C., there are often limitations to thepossibilities of employing a discontinuous method, which in fact ispractically restricted to the production of small shaped articles. Thecomponents are preferably continuously mixed in a mixing chamber with alow residence time by the usual methods employed for producingpolyurethane foams and then hardened in a shaping operation. This may bedone, for example, by pouring the liquid or pasty mixtures into molds orapplying them to surfaces or filling them into cavities, joints orcracks and the like.

When mixing is carried out, the proportion by weight of total organiccontent to silicate content may vary within wide limits, e.g. between99:1 and 1:99. Preferably, the ratio of organic constituent to silicatecontent is between 98:2 and 5:95. Optimum use properties, in particularhigh strength, elasticity, dimensional stability under heat and flameresistance are obtained when mixing ratios of organic content tosilicate content are between 70:30 and 20:80.

This range is therefore particularly preferred.

The whole organic component should preferably have such a compositionthat, based on the isocyanate component (a), the ionic group ofcomponent (c) amounts to 2-200 milliequivalents per 100 of component (a)and/or the nonionic-hydrophilic group of component (c) amounts to 1-50percent by weight, based on component (a).

From the proportions indicated above, it will be seen that theproportion of total organic component to silicate solution used forproducing this composite material of polymer and silica gel is notcritical. This is particularly advantageous because in continuousmethods of production using delivery apparatus and mixing chambers itobviates the necessity for exact measurement of the quantities, andsturdy delivery devices such as gearwheel pumps may therefore be used.

The activity of the reaction mixture can be adjusted mainly by thequantity and nature of the ionic and/or nonionic-hydrophilic groups.Products with a low silicate content, e.g. between 1% and 30%, arepreferably produced in cases where the organic polymer properties of theproduct are required to predominate and the silicate content isrequired, for example, to improve the binding of the fillers, inparticular the so-called inactive fillers such as chalk, heavy spar,gypsum, anhydrite, clay or kaolin.

Small quantities of silicate solutions are indicated also where anisocyanate prepolymer is to be hardened with water to form a non-porous,homogeneous plastic. Since, as is well known, the reaction betweenNCO-groups and water is accompanied by the evolution of CO₂, it ispractically restricted to the production of foams. Pore formation canalso not be prevented when water glass solutions are used inconventional elastomer formulations, due to the evolution of CO₂. Thereaction of the three starting components used according to theinvention, on the other hand, leads to a product with considerablyreduced pore formation, and if the three components are used in suitablyadjusted proportions, which can easily be determined in empirically, acompletely pore-free material which is chain lengthened or crosslinkedwith water is obtained. High-quality homogeneous polyureas in this waybecome available by a simple, solvent-free direct process. The desiredreaction velocity can easily be adjusted by varying the ionic and/ornonionic-hydrophilic group content.

A high silicate content, e.g. 80-99%, is desired in cases where theproperties of an inorganic silicate plastic are the most important, inparticular high temperature resistance and complete incombustibility. Inthat case, the function of the isocyanate component is that of anon-volatile hardener whose reaction product is a high-molecular weightpolymer which reduces the brittleness of the product. This elasticizingeffect makes these combinations of polyisocyanate and organic compound(c) superior to the usual acid-based hardeners. The hardening timesgenerally increase as the hydrophilic group content decreases.Combinations of this kind, and especially those which do not have asufficient hardening effect, may, of course, be used in combination withhardeners which split off acids. In that case, the organic constituentsact mainly as elasticizing component.

Mixtures of the three starting components which contain more than 30% ofwater are preferably used for producing thin layers such as surfacecoatings or putties, adhesive bonds or grouting compositions andparticularly for producing foams.

When producing foams by the process according to the invention it isadvisable to use blowing agents, even when using NCO-prepolymers whichgive rise to the evolution of carbon dioxide. The blowing agents whichare suitable for this purpose are inert liquids boiling within a rangeof -25° C. to +80° C. and preferably -15° C. to +40° C. They arepreferably insoluble in the silicate solution and they are used inquantities of 0-50% by weight, preferably 2-30% by weight, based on thereaction mixture.

Suitable organic blowing agents are e.g. acetone, ethyl acetate,methanol, ethanol, halogen-substituted alkanes such as methylenechloride, chloroform, ethylidene chloride, vinylidene chloride,monofluorotrichloromethane, chlorodifluoromethane ordichlorodifluoromethane, butane, hexane, heptane or diethyl ether.Substances which decompose at temperatures above room temperature toliberate gases such as nitrogen, for example azo compounds such asazoisobutyric acid nitrile, may also act as blowing agents. Otherexamples of blowing agents and details concerning the use of blowingagents are described in Kunststoff-Handbuch, Volume VII, published byVieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on pages 108and 109, 453 to 455 and 507 to 510.

Catalysts which promote the reaction of isocyanates with reactivehydrogen are also often used according to the invention in catalyticamounts. Catalysts known per se may be used, e.g. tertiary amines suchas triethylamine, tributylamine, N-methyl-morpholine,N-ethyl-morpholine, N-cocomorpholine, N,N,N',N'-tetramethyl-ethylenediamine, 1,4-diaza-bicyclo(2,2,2)-octane, N-methyl-N'-dimethylaminoethylpiperazine, N,N-dimethyl benzylamine,bis-(N,N-diethylaminoethyl)-adipate, N,N-diethyl benzylamine,pentamethyl diethylene triamine, N,N-dimethyl cyclohexylamine,N,N,N',N'-tetramethyl-1,3-butane diamine, N,N-dimethyl-β-phenylethylamine, 1,2-dimethyl imidazole or 2-methyl imidazole.

Suitable tertiary amine catalysts with hydrogen atoms which are reactivewith isocyanate groups include e.g. triethanolamine,triisopropanolamine, N-methyl-diethanolamine, N-ethyl-diethanolamine,N,N-dimethyl-ethanolamine and their reaction products with alkyleneoxides such as propylene oxide and/or ethylene oxide.

Silaamines which have carbon-silicon bonds as described e.g. in GermanPatent Specification No. 1,229,290 may also be used as catalysts, e.g.2,2,4-trimethyl-2-silamorpholine or1,3-diethylaminomethyl-tetramethyl-disiloxane.

Bases which contain nitrogen, such as tetraalkyl ammonium hydroxides,alkali metal hydroxides such as sodium hydroxide, alkali metalphenolates such as sodium phenolate or alkali metal alcoholates such assodium methylate may also be used as catalysts. Hexahydrotriazines arealso suitable catalysts.

Organic metal compounds may also be used as catalysts according to theinvention, particularly organic tin compounds.

The organic tin compounds used are preferably tin(II) salts ofcarboxylic acids such as tin(II)-acetate, tin(II)-octoate, tin(II)-ethylhexoate and tin(II)-laurate and the dialkyl tin salts of carboxylicacids such as dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tinmaleate or dioctyl tin diacetate.

Other representatives of catalysts which may be used according to theinvention and details concerning the action of the catalysts have beendescribed in Kunststoff-Handbuch, Volume VII, published by Vieweg andHochtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 96 to 102.

The catalysts are generally used in any catalytic amount, preferably ina quantity of between about 0.001% and 10% by weight, based on thequantity of polyisocyanate.

Surface-active additives (emulsifiers and foam stabilizers) may also beused according to the invention. Suitable emulsifiers include e.g. thesodium salts of ricinoleic sulphonates or of fatty acids or salts offatty acids with amines such as oleic acid diethylamine or stearic aciddiethanolamine. Alkali metal or ammonium salts of sulphonic acids, forexample of dodecyl benzene sulphonic acid or dinaphthyl methanedisulphonic acid or of fatty acids such as ricinoleic acid or ofpolymeric fatty acids may also be included as surface-active additives.

The foam stabilizers used are mainly water-soluble polyether siloxanes.These compounds generally have a polydimethyl siloxane group attached toa copolymer of ethylene oxide and propylene oxide. Foam stabilizers ofthis kind have been described e.g. in U.S. Pat. No. 3,629,308.

Reaction retarders, e.g. substances which are acid in reaction such ashydrochloric acid or organic acid halides, cell regulators known per sesuch as paraffins or fatty alcohols or dimethyl polysiloxanes, pigments,dyes, flame-retarding agents known per se such as tris-chloroethylphosphate or ammonium phosphate and polyphosphate, stabilizers againstaging and weathering, plasticizers, fungistatic and bacteriostaticsubstances and fillers such as barium sulphate, kieselguhr, carbon blackor whiting may also be used according to the invention.

Other examples of surface-active additives, foam stabilizers, cellregulators, reaction retarders, stabilizers, flame-retarding substances,plasticizers, dyes, fillers and fungistatic and bacteriostaticsubstances which may also be used according to the invention and detailsconcerning their use and mode of action have been described inKunststoff-Handbuch, Volume VI, published by Vieweg and Hochtlen,Carl-Hanser-Verlag, Munich 1966, e.g. on pages 103 to 113.

Additives which even further improve the fire characteristics of theseplastics are particularly important and therefore it is preferred toinclude them. Apart from the usual flame-retarding agents, these includein particular halogenated paraffins and inorganic salts of phosphoricacid.

Production of foams according to the invention is basically carried outby mixing the above described reactants in one or several stages in adiscontinuously or continuously operating mixing apparatus and thenleaving the mixture to foam up and solidity, in most cases outside themixing apparatus in molds or on suitable supports. The required reactiontemperature of between about 0° C. and 200° C., preferably between 30°C. and 160° C., can be achieved either by preheating one or more of thereactants before the mixing process or by heating the mixing apparatusitself or by heating the reaction mixture after it has been prepared.One may, of course, also use combinations of these or other methods foradjusting the reaction temperature. In most cases, sufficient heat isevolved during the reaction to enable the reaction temperature to riseabove 50° C. after onset of the reaction or of foaming.

The reactants may, however, also be reacted by the known one-stepprocess, prepolymer process or semi-prepolymer process, often usingmechanical devices such as those described in U.S. Pat. No. 2,764,565.Details concerning apparatus which may also be used according to theinvention have been described in Kunststoff-Handbuch, Volume VI,published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g.on pages 121 to 205.

Exceptionally high-grade plastics are obtained by the process accordingto the invention if hardening is carried out at temperatures above 20°C., in particular 50°-200° C. So much heat is liberated even without theexternal supply of heat, especially in combinations of polyisocyanateswhich contain 10-40% of NCO-groups and alkali metal silicate solutions,that the water begins to evaporate. Temperatures above 150° C. areeasily reached in the interior of foam blocks.

It appears that under these conditions particularly marked interactionstake place between the inorganic and organic polymer and a particularlyfirm bond is formed between them so that the resulting materials are notonly rock-hard but at the same time also highly elastic and thereforequite exceptionally shock-resistant and resistant to breakage.

If the quantity of heat evolved in the reaction between the componentsis not sufficient, mixing may easily be carried out at a highertemperature, e.g. between 40° and 100° C. In special cases, mixing mayalso be carried out above 100° C., up to about 150° C. under pressure,so that when the material is discharged from the apparatus, the releaseof pressure is accompanied by foaming.

If production of the foam is carried out at an elevated temperature, onemay, of course, also use higher boiling blowing agents such as hexane,dichloroethane, trichloroethane, carbon tetrachloride or light petrol.On the other hand, the water contained in the mixture may take over thefunction of blowing agent. Fine metal powders such as powders ofcalcium, magnesium, aluminum or zinc may function as blowing agents dueto the evolution of hydrogen if the water glass is sufficientlyalkaline, and these powders at the same time have a hardening andstrengthening effect on the product.

Foams may also be produced with the aid of inert gases, particularlyair. For example, one of the reactants may be foamed up with air andthen mixed with the other components. Mixing of the components may alsobe achieved, e.g. with the aid of compressed air which results in thedirect formation of a foam which then hardens when shaped.

For any given formulation of components, the properties of the foamsobtained, e.g. their density in the moist state, depends to some extenton the details of the mixing process such as the nature and speed of thestirrer, the form of the mixing chamber and the selected reactiontemperature when foaming is started. This density may vary from about0.005 to 1.2 g/m³ and in most cases moist fresh foams with densities ofbetween 0.02 and 0.8 g/cm³ are obtained. When dry, the foams may have anopen-celled or closed-celled character. In most cases, they aresubstantially open-celled with densities of between 0.01 and 0.6 g/cm³.

The characteristics of the reaction mixtures provide many possibleapplications for the process according to the invention and hence manyfields of application, some of which will be outlined below. Thepossibility of either leaving the water in the hardened mixtures as adesirable constituent in the foam or of protecting the foam against lossof water by suitable coating or laminating or of partly or completelyremoving the water by suitable drying processes, e.g. in a heatingcupboard or with hot air, infrared heating, ultrasound or highfrequency, may be adapted to the desired fields of application from caseto case.

The reaction mixture which contains blowing agent may, for example, bespread-coated on warm or cold supports or supports exposed to IR or HFradiation, or after passing the mixing apparatus the reaction mixturemay be sprayed on these supports with the aid of compressed air or bythe airless spraying process. The reaction mixture then foams up on thesupports and hardens to form a filling or insulating or moistureproofing coating. The foaming reaction mixture may also be forced, castor injection-molded into cold or heated molds and in these molds, whichmay be relief molds, solid molds or hollow molds, it may be left toharden, optionally under pressure and at room temperature ortemperatures of up to 200° C., optionally using a centrifugal castingprocess. At this stage, reinforcing elements in the form of inorganicand/or organic or metal wires, fibers, non-woven webs, foams, fabrics,supporting structures etc. may be incorporated. This may be achieved,for example, by the fibrous web impregnation process or by processes inwhich the reaction mixtures and reinforcing fibers are together appliedto the mold, for example by means of a spray apparatus. The moldedproducts obtainable in this way may be used as building elements, e.g.in the form of optionally foamed sandwich elements which may be useddirectly or subsequently laminated with metal, glass, plastics, etc.,the good fire characteristics of the material in the moist or dry statebeing a considerable advantage in these elements. On the other hand, theproducts may be used as hollow bodies, e.g. as containers for goodswhich are required to be kept moist or cool, or they may be used asfilter materials or exchangers, as catalyst carriers or carriers ofother active substances, as decoration elements, furniture componentsand cavity fillings. They may also be used as heavy-duty lubricants andcoolants or carriers of such substances, e.g. in metal extrusionpresses. Their use in model and mold building and in the production ofmolds for metal casting may also be considered.

One preferred method consists of letting the foaming process proceedhand in hand with hardening, for example by preparing the reactionmixture in a mixing chamber and at the same time adding the readilyvolatile blowing agent such as dichlorodifluoromethane,trichlorofluoromethane, butane, isobutylene or vinyl chloride so thatwith suitable choice of the mixing temperature the reaction mixturefoams up on leaving the mixing chamber due to evaporation of the blowingagent and at the same time hardens due to the action of the hardener sothat the resulting foam, which may still contain emulsifiers and foamstabilizers and other auxiliary agents, becomes fixed. Furthermore, thereaction mixture which initially is still a thin liquid may be foamed upby introducing gases such as air, methane, CF₄ or inert gases,optionally under pressure, this foam being converted into the requiredform and left to harden. Alternatively, the silicate- ornonionic-hydrophilic prepolymer solution which may contain foamstabilizers such as wetting agents, foam-forming agents, emulsifiers andoptionally also other organic or inorganic fillers or diluents may beconverted into a foam by gasifying it and this foam may then be mixedwith the counter components in a mixing apparatus and optionally alsowith hardener and then left to harden.

According to a preferred method, the organic component (c) is firstmixed with the alkali metal silicate solution and optionally activatorand/or emulsifier and then mixed with the polyisocyanate to whichblowing agent has been added, so that the mixture hardens while foamingup.

Instead of blowing agents, inorganic or organic finely divided hollowparticles such as hollow expanded beads of plastics, straw and the likemay be used for producing the foams.

The foams obtainable in this way may be used in the dry or moist state,optionally after a compating or tempering process, optionally underpressure, as insulating materials, cavity fillings, packaging materialsand building materials which have good solvent resistance and firecharacteristics. They may also be used as light-weight building bricksin the form of sandwiches, e.g. with metal covering layers for use inhouse-building and the construction of motor vehicles and aircraft.

The reaction mixtures may also be foamed up and hardened while in theform of droplets dispersed e.g. in petroleum hydrocarbons or while theyare under conditions of free fall. Foam beads are obtained in this way.

Furthermore, organic and/or inorganic particles which are capable offoaming or have already been foamed, e.g. particles of expanded clay,blown glass, wood, popcorn, cork, hollow beads of plastics such as vinylchloride polymers, polyethylene, styrene polymers or foam particles ofthese polymers or of other polymers such as polysulphone, polyepoxide,polyurethane, urea formaldehyde, phenol formaldehyde or polyimidepolymers may be incorporated in the foaming reaction mixtures while theyare still fluid, or heaps of these particles may be permeated with thereaction mixtures to produce insulating materials which have good firecharacteristics.

If the blowing agent which is capable of evaporating or liberating gasesbelow a given temperature, for example a hydrocarbon or halogenatedhydrocarbon, is added at this temperature to a mixture of aqueoussilicate solutions and hardeners optionally also containing inorganicand/or organic additives, then the resulting mixture, which is at firstliquid, may be used not only for producing uniform foams or foams whichcontain other foamed or unfoamed fillers but also for permeating wovenand non-woven fibrous webs, grids, constructional parts or otherpermeable structures with foamed material to produce composite foamswhich have special properties, e.g. advantageous fire characteristics,which may be used directly as constructional elements in the buildingindustry, furniture industry or motor vehicle and aircraft industries.

The foams according to the invention may also be added in a crumbly formto soil, optionally with the addition of fertilizers andplant-protective agents, to improve the agricultural consistency of thesoil. Foams which have a high water content may be used as substratesfor the propagation of seedlings, shoots and plants or for cut flowers.The mixtures may be sprayed on terrain which is impassible or too loose,such as dunes or marshes, to strengthen such terrain so that it will befirm enough to walk on within a short time and it will be protectedagainst erosion.

The reaction mixtures proposed here are also important in the case offire or disaster because they can be sprayed on articles which arerequired to be protected, and the water contained in them cannot rundown the surface of the protected article and cannot evaporate rapidly,so that a very effective protection against fire, heat or radiation isobtained since the hardened mixture cannot be heated to temperaturesmuch above 100° C. so long as it still contains water, and it willabsorb IR or nuclear radiation.

Since the mixtures can easily be sprayed, they can be used to formeffective protective walls and protective layers in mines in the case ofaccident or also for routine work, for example by spraying them onfabrics or other surfaces or grids or also simply on walls. Aparticularly important characteristic for this purpose is that themixtures harden rapidly.

In the same way, the foaming mixtures may also be used in undergroundand surface engineering and road building for erecting walls and igloosand for sealing, filling, plastering, priming, insulating and decoratingand as coatings, flooring compositions and linings. Their use asadhesives or mortar or casting compounds, optionally with inorganic ororganic fillers, may also be considered.

Since the hardened foams produced by the process according to theinvention are highly porous after drying, they are suitable for use asdrying agents because they are then able to absorb water again. On theother hand, they may be charged with active substances or used ascatalyst carriers or filters or absorbents.

Auxiliary agents which may be added to the reaction mixture orintroduced subsequently, such as emulsifiers, detergent raw materials,dispersing agents, wetting agents, perfumes or substances which renderthe mixture hydrophobic enable the properties of foams to be modified asdesired in the aqueous or dry state.

On the other hand, the foams in theiraqueous or dried or impregnatedstate may subsequently be lacquered, metallized, coated, laminated,galvanized, vapor-treated, bonded or flocked. Forming operations may becarried out on the shaped articles in their aqueous or dried state, forexample by sawing, cutting, drilling, planing, polishing or other suchprocesses.

The shaped products, with or without filler, may be further modified intheir properties by thermal after-treatment, oxidation processes,heat-pressing, sintering processor or surface melting or othercompacting processes.

The molds may suitably be made of inorganic and/or organic foamed orunfoamed material such as metals, e.g. iron, nickel, refined steel orlacquered or teflon coated aluminum or precelain, glass, gypsum, cement,wood or plastics such as PVC, polyethylene, epoxy resins, polyurethanes,ABS, polycarbonate etc.

The foams obtained according to the invention may be surface-dried or incases where they are substantially permeable structures such ashigh-grade open-celled foams or porous materials they may also be driedby centifuging, vacuum treatment, blowing air through them or removingthe water by washing dehydrating liquids through them (optionally withheating) or gases such as methanol, ethanol, acetone, dioxane, benzene,chloroform and the like or air, CO₂ or steam. The moist or dried shapedproducts may also be subsequently rinsed or impregnated with aqueous ornon-aqueous acid, neutral or basic liquids or gases such as hydrochloricacid, phosphoric acid, formic acid, acetic acid, ammonia, amines,organic or inorganic salt solutions, lacquer solutions, solutions ofmonomers which have been polymerized or are yet to be polymerized, dyesolutions, galvanization baths or solutions with catalysts or catalystprecursors or perfumes.

The new composite plastics are also suitable for use as constructionalmaterials because they have a high tensile strength and compressionresistance and are tough and stiff and yet elastic and have a highdimensional stability under heat and flame resistance.

The excellent heat-insulating and sound-absorbing capacity of thesefoams should also be emphasized, properties which in combination withthe excellent fire resistance and heat resistance open up newpossibilities of application in the insulating field.

Thus for example high-quality light-weight building panels can beproduced either by cutting or sawing continuously foamed blocks or byfoaming such panels in molds, optionally under pressure, this moldingprocess being particularly suitable also for complicated shapes. Bysuitably controlling the operating conditions it is also possible toobtain molded products which have a dense outer skin.

The process according to the invention is particularly suitable,however, for in situ foaming on the building site. Any hollow moldsnormally produced by shuttering in forms can be obtained by casting andfoaming.

Cavities, joints and cracks can also easily be filled with the reactionmixture, a very firm bond being obtained between the materials which arejoined together in this way. The reaction mixtures may also be used toproduce insulating indoor plasters simply by spraying.

In many cases, the materials obtained can be used instead of wood orhard fiber board. They can be worked by sawing, grinding, planing,nailing, drilling and cutting and are therefore versatile in their usesand possible applications.

Very brittle light-weight foams which can be obtained e.g. with veryhigh silicate contents or by using combinations with brittleorgano-polymers, can easily be crushed in suitable apparatus to formdust-fine powders which can be used for many purposes as organo-modifiedsilica fillers. The organo-modification insures good surface interactionwith polymers and in some cases also a certain surface thermoplasticitywhich enables high-quality molding materials to be obtained with whichtopochemical surface reactions can be carried out by the addition ofcrosslinking agents.

For many purposes, additional fillers in the form of particulate orpulverulent materials are incorporated in the mixtures ofpolyisocyanate, organic component (c) and alkali metal silicates and/orsilica sols.

The fillers may be solid inorganic or organic substances used e.g. inthe form of powder, granulate, wire, fibers, dumb-bell-shaped particles,crystallites, spirals, rods, beads, hollow beads, foam particles,fleeces, woven or knitted fabrics, tapes, foil pieces etc., for exampledolomite, chalk, clay, asbestos, basic silicic acids, sand, talcum, ironoxide, aluminum oxide and hydroxides, alkali metal silicates, zeolites,mixed silicates, calcium silicates, calcium sulphates, aluminosilicates, cements, basalt wool or powder, glass fibers, carbon fibers,graphite, carbon black, Al-, Fe-, Cu- and Ag-powder, molybdenumsulphide, steel wool, bronze or copper fabrics, silicon powder, expandedclay particles, hollow glass beads, glass powder, lava and pumiceparticles, wood chips, wood meal, cork, cotton, straw, popcorn, coke andparticles of filled or unfilled, foamed or unfoamed, stretched orunstretched organic polymers. Among the numerous suitable organicpolymers, the following are mentioned as examples, which may be used,e.g. as powders, granulates, foam particles, beads, hollow beads,particles which can be foamed but have not yet been foamed, fibers,tapes, woven and non-woven webs, etc.: polystyrene, polyethylene,polypropylene, polyacrylonitrile, polybutadiene, polyisoprene,polytetrafluoroethylene, aliphatic and aromatic polyesters, malamineurea resins or phenol resins, polyacetal resins, polyepoxides,polyhydantoins, polyureas, polyethers, polyurethanes, polyimides,polyamides, polysulphones, polycarbonates and, of course, any copolymersthereof.

In principle, the composite materials according to the invention may befilled with considerable quantities of fillers without thereby losingtheir valuable properties. Composite material in which the inorganiccomponent predominates are preferably filled with inorganic fillers toobtain a reinforcing effect while composite materials in which thesilicate content predominates are preferably filled with organicfillers.

Particularly preferred fillers are chalk, talcum, dolomite, gypsum,clay, anhydrite, glass, carbon and the usual plastics and rubber waste.

Products which have a low silicate content are particularly suitable forproducing rapidly hardening high-quality surface coatings which haveexcellent adherence and wear resistance and for producing elastomerswith high strength and high modulus.

For producing surface coatings, adhesive bonds, putties, interlayers,particularly on porous materials, the incorporation of a hardener isfrequently unnecessary because the carbon dioxide from the atmosphere issufficient to act as hardener.

For such applications, it is preferable to use polyisocyanates with alow isocyanate content e.g. less than 5%. The mixtures obtained in thisway have a long pot life and can also be applied in thin layers whichgradually harden in the course of time.

If only a small quantity of hardener (e.g. CO₂) is liberated in thecourse of the mixing process, a pasty or dough-like material which canbe shaped in any way desired is obtained as a result of partialhardening accompanied by increase in viscosity. This material may beworked up into a shaped product and hardened at a later date, e.g. bydrying in air or by heating.

Particularly interesting in cases where the materials are to be workedup as putties, fillers which are to be applied by trowel, groutingcompositions, mortar and the like is a process of two-stage ormulti-stage hardening in which, for example, CO₂ is rapidly split off inthe first stage, (e.g. by reaction of NCO-groups with water) with theresult that the inorganic-organic composite material is brought into aplastic or thermoplastic, workable form, the final hardening then takingplace more slowly in a second stage, e.g. by hydrolysis of ahigh-molecular weight or low-molecular weight ester.

In the thermoplastic intermediate stage, the product may also be workedup by injection-molding or extrusion or in a kneader.

In many cases, the materials in this intermediate stage may also bemixed with water, organic solvents, plasticizers, extenders or fillersand thereby modified in numerous ways and applied.

The materials according to the invention are also suitable for use asfinishes for treating fibers in impregnating agents. For this purposethey may be applied either as the finished mixture of organic componentand silicate component or as two separate baths. It is thereforepreferable first to apply that component which adheres more firmly tothe fiber, in other words the isocyanate component on organic materialand the silicate component on inorganic material.

Furthermore, fibers and sheet structures which can be used e.g. formanufacturing synthetic incombustible paper or for manufacturingnon-woven webs may be produced by extruding the mixtures through dies orslots.

The invention is further illustrated but is not intended to be limitedby the following examples in which all parts and percentages are byweight unless otherwise specified.

EXAMPLES

Starting materials:

(a) Polyisocyanate component:

A. 1. Diisocyanatodiphenylmethane is distilled from the crudephosgenation product of an aniline-formaldehyde condensate until thedistillation residue has a viscosity of 400 cP at 25° C. (dinuclearcontent: 45.1% by weight, trinuclear content: 22.3% by weight,proportion of higher-nuclear polyisocyanates: 32.6% by weight)NCO-content 30-31% by weight.

A 2. Similarly prepared polyisocyanate with a viscosity of 700 cP at 25°C. (dinuclear content: 40.6% by weight, trinuclear content: 27.2% byweight, proportion of higher-nuclear polyisocyanates: 32.2% by weight)NCO-content: 29-30% by weight.

A 3. Similarly prepared polyisocyanate with a viscosity of 1700 cP at25° C. (dinuclear content: 40.3% by weight, trinuclear content: 34.0% byweight, proportion of higher-nuclear polyisocyanates: 25.7% by weight)NCO-content: 28-29% by weight.

(b) Silicate component:

B 1. Sodium silicate (water glass), 44% solids, molecular weight ratioNa₂ O:SiO₂ = 1:2

B 2. Sodium silicate (water glass), 34% solids, molecular weight ratioNa₂ O:SiO₂ = 1:3

(c) Organic component c:

C 1. Polyethylene oxide monoalcohol with a molecular weight of 1145started on n-butanol.

C 2. Polyethylene oxide monoalcohol with a molecular weight of 782started on n-butanol.

C 3. Polyethylene oxide monoalcohol with a molecular weight of 1978started on n-butanol.

C 4. Aqueous solution of the sodium salt of the monoester of1,2-tetrahydrophthalic acid and 1,1,1-trimethylol-propane, 50% solids.

C 5. Aqueous solution of sodium salt ofp-(β-γ-dihydroxy-propyloxy)-benzenesulphonic acid, 30% solids.

C 6. Aqueous solution of N-(2-aminoethyl)-2-aminoethane sulphonic acidsodium salt, 45% solids.

C 7. Aqueous solution of aminoethane sulphonic acid, 20.2% solids.

C 8. Aqueous solution of the sodium salt of dimethylol-propionic acid,50% solids.

C 9. Aqueous solution of the sodium salt of2,2'-bis-hydroxy-methyl-ethane sulphonic acid, 50% solids.

C 10. Aqueous solution of the sodium salt of 2-hydroxyethane sulphonicacid, 50% solids.

C 11. Polyethylene oxide monoalcohol with a molecular weight of 1546started on nonyl phenol.

C 12. Aqueous solution of the reaction product of N-butyldiethanolamineand dimethyl sulphate (molar ratio 1:1), 50% solids, adjusted to pH 10with 1 n NaOH.

C 13. Aqueous solution of disodium tartrate, 40% solids.

EXAMPLE 1

    ______________________________________                                        150 g of polyisocyanate A 1                                                                                   component I                                   20 g  of trichlorofluoromethane                                               150 g of silicate component B 1                                               1.5 g of triethylamine                                                        0.2 g of emulsifier, sodium salt of                                                                           component II                                        a sulphochlorinated C.sub.10 -C.sub.14                                        paraffin mixture                                                        1.5 g of organic component C 6                                                                         }      component III                                 ______________________________________                                    

A preliminary mixture was first prepared from components II and III andthis was then vigorously mixed with component I with the aid of ahigh-speed stirrer for 15 seconds. The reaction mixture was poured intoa paper packet where it began to foam up after 150 seconds andsolidified 13 seconds later. A hard, inorganic-organic foam was obtainedwhich had a not quite regular cell structure and which after drying (3h/120° C.) had a gross density of 700 kg/m³ and a compression strengthof 213.6 kp/cm².

EXAMPLE 2

    ______________________________________                                        150 g  of polyisocyanate A 1                                                                                  component I                                   20 g   of trichlorofluoromethane                                              150 g  of silicate component B 1                                              2.5 g  of triethylamine         component II                                  0.2 g  of emulsifier according                                                       to Example 1                                                           1.5 g  of organic component C 6                                                                        }      component III                                 ______________________________________                                    

The components were mixed as described in Example 1. The reactionmixture started to foam up after 40 seconds and had hardened only 6seconds later. A hard, inorganic-organic foam with a coarse porestructure and a gross density of 310 kg/m³ was obtained.

EXAMPLE 3

    ______________________________________                                        150 g  of polyisocyanate A 1                                                                                  component I                                   20 g   of trichlorofluoromethane                                              150 g  of silicate component B 2                                              1.5 g  of triethylamine         component II                                  0.2 g  of emulsifier according                                                       to Example 1                                                           4 g    of organic component C 6                                                                        }      component III                                 ______________________________________                                    

The procedure was the same as in Example 1 except that the threecomponents were mixed simultaneously and the mixture of all threecomponents was stirred for 30 seconds. The reaction mixture began tofoam up after 65 seconds and had solidified 13 seconds later.

A hard, inorganic-organic foam with a fine, not quite regular cellstructure was obtained which had a gross density of 572 kg/m³ and acompression strength of 151.0 kp/cm² after tempering for 3 hours at 120°C.

EXAMPLE 4

    ______________________________________                                        150 g  of polyisocyanate A 1                                                                                  component I                                   20 g   of trichlorofluoromethane                                              150 g  of silicate component B 1                                              2.0 g  of triethylamine         component II                                  0.2 g  of emulsifier according                                                       to Example 1                                                           20 g   of organic component C 6                                                                        }      component III                                 ______________________________________                                    

Components I and II are first separately vigorously mixed and then allthe three components were added together and immediately mixedvigorously together with a high-speed stirrer for 10 seconds. Thereaction mixture was poured into a paper mold where it began to foam upafter 110 seconds and was still plastic after 1 minute. After 8 minutesit had solidified to a rock-hard inorganic-organic foam with a fine,slightly irregular pore structure. The gross density of this foam was736 kg/m³.

EXAMPLE 5

    ______________________________________                                        105 g                                                                              of polyisocyanate A 1                                                    45 g of sulphonated polyisocyanate A 1                                             obtained by reacting polyisocyanate                                           A 1 with gaseous sulphur trioxide                                             at 50° C. The sulphonated poly-                                                                    component I                                       isocyanate A 1 has a sulphur content                                          of 0.95% by weight and a viscosity                                            of 1800 cP at 25° C.                                              20 g of trichlorofluoromethane                                                150 g                                                                              of silicate component B 1                                                2.0 g                                                                              of triethylamine            component II                                 0.2 g                                                                              of emulsifier according to Example 1                                     15 g of organic component C 6                                                                            }     component III                                ______________________________________                                    

Mixing was carried out as in Example 4. The mixing time was 15 seconds.The reaction mixture began to foam up after 95 seconds and hassolidified to a hard, inorganic-organic foam 25 seconds later. The grossdensity of the product was 585 kg/m³, the compression strength 147.2kp/cm².

EXAMPLE 6

    ______________________________________                                        75 g of polyisocyanate A 1                                                    75 g of sulphonated polyisocyanate A 1                                                                         component I                                       according to Example 5                                                   20 g of trichlorofluoromethane                                                150 g                                                                              of silicate component B 1                                                1.5 g                                                                              of triethylamine            component II                                 0.2 g                                                                              of emulsifier according to Example 1                                     2.2 g                                                                              of organic component C 6                                                                            }     component III                                ______________________________________                                    

Mixing of the components was carried out as in Example 1. The reactionmixture began to foam up after 23 seconds and had solidified to arock-hard foam 10 seconds later. At that point, the foam had reached aninternal temperature of 102° C. The hard-elastic inorganic-organic foamobtained had a regular cell structure and medium pore size. After 3hours tempering at 120° C., the foam had a gross density of 108 kg/m³and a compression strength of 7.6 kp/cm².

EXAMPLE 7

    ______________________________________                                        75 g of polyisocyanate A 1                                                    75 g of sulphonated polyisocyanate A 1                                                                         component I                                       according to Example 5                                                   20 g of trichlorofluoromethane                                                150 g                                                                              of silicate component B 1                                                1.5 g                                                                              of triethylamine            component II                                 0.2 g                                                                              of emulsifier according to Example 1                                     4.4 g                                                                              of organic component C 7                                                                            }     component III                                ______________________________________                                    

The inorganic-organic foam was prepared as in Example 1. Mixing time ofthe components was 15 seconds and time until the onset of foaming 27seconds. 14 seconds later a rock-hard foam with a regular cell structureand fine pores was obtained. After 3 hours tempering at 120° C. it had aunit weight of 203 kg/m³ and a compression strength of 22.3 kp/cm².

EXAMPLE 8

    ______________________________________                                        75 g of polyisocyanate A 1                                                    75 g of sulphonated polyisocyanate A 1                                                                         component I                                       according to Example 5                                                   20 g of trichlorofluoromethane                                                150 g                                                                              of silicate component B 1                                                1.5 g                                                                              of triethylamine            component II                                 0.2 g                                                                              of emulsifier according to Example 1                                     6.6 g                                                                              of organic component C 8                                                                            }     component III                                ______________________________________                                    

Mixing was carried out as in Example 1. The mixing time was 15 seconds.The foaming process began after 24 seconds and was completed 7 secondslater. A hard, inorganic-organic foam with a fine regular cell structurewas obtained. After tempering (3 hours at 120° C.) it had a grossdensity of 166 kg/m³ and a compression strength of 16.8 kp/cm².

EXAMPLES 9-20

    ______________________________________                                        polyisocyanate A 1                                                                                         component I                                      trichlorofluoromethane                                                        silicate component B 1                                                        amine catalyst consisting of 75% by                                           weight of N,N-dimethylaminoethanol                                            and 25% by weight of diazabicyclooctane                                                                    component II                                     polyether polysiloxane                                                        foam stablizer of ex.4 of U.S. Pat. No. 3,658,864.                            organic component c                                                                                        component III                                    optionally water                                                              ______________________________________                                    

Each component was first thoroughly mixed separately and then componentII and component III were simultaneously added to component I and thethree components were mixed in a cardboard beaker with the aid of ahigh-speed stirrer for 15 seconds. The liquid reaction mixture waspoured into a paper packet where it began to foam up after a short timeand hardened to an inorganic-organic light-weight with evolution ofheat.

The foams at first contain water and are finely porous, largelyopen-celled with a regular cell structure and in most cases tough andelastic, depending on the proportion of organic constituents. The foamsare distinguished by their excellent fire characteristics, goodinsulating capacity in the dry state and stability of their contours athigh temperatures (above 150° C.). The mechanical strength propertiesdepend on the composition but may be regarded as good in relation totheir density.

The examples are summarized in Table 1.

The abbreviations have the following meanings:

t_(R) = stirring time, mixing time of the mixture of component I,component II and component III

t_(L) = lying time, time from onset of mixing to onset of foaming

t_(A) = setting time, time from begin of mixing to hardening.

                  Table 1                                                         ______________________________________                                        component I       component II                                                       Polyiso- Trichloro-                                                                              Silicate                                                                              Amine                                              cyanate  fluoro-   component                                                                             cata-                                       Example                                                                              A 1      methane   1       lyst  Stabilizer                            No.    (g)      (g)       (g)     (g)   (g)                                   ______________________________________                                         9     150      20        150     2.0   1.5                                   10     150      20        150     2.0   1.5                                   11     150      20        150     2.0   1.5                                   12     150      20        150     2.0   1.5                                   13     150      20        150     2.0   1.5                                   14     150      20        150     2.0   1.5                                   15     200      --        50      1     1.5                                   16     200      --        50      1     1.5                                   17     150      20        200     2     1.5                                   18     150      20        200     2     1.5                                   19     200      --        10      1     1.5                                   20     200      --        10      1     1.5                                   component III                                                                         Organic                                                                       component c                                                           Example          Quantity Water t.sub.R                                                                            t.sub.L                                                                            t.sub.A                             No.       Type   (g)      (g)   (sec)                                                                              (sec)                                                                              (sec)                               ______________________________________                                         9        C 1    15       15    15   60   110                                 10        C 1     5        5    15   64    94                                 11        C 1    35       35    15   76   124                                 12        C 11   13       27    15   83   225                                 13        C 3    20       20    15   75   140                                 14        C 2    20       20    15   45   135                                 15        C 3    20       20    15   65    90                                 16        C 2    20       20    15   60    90                                 17        C 3    20       20    15   66   120                                 18        C 2    20       20    15   66   135                                 19        C 3    20       20    15   66   135                                 20        C 2    20       20    15   60   125                                            Density                                                                       (kg/m.sup.3)     Compression                                       Example    after drying     strength                                          No.        fresh    2h/120° C                                                                          (kp/cm.sup.2)                                 ______________________________________                                         9         --       20          0.17                                          10         --       23          0.26                                          11         --       47          0.23                                          12         34       25          --                                            13         27       21                                                        14         23       18                                                        15         16       15                                                        16           12.4   12                                                        17         43       32.8                                                      18         16       15.4                                                      19         16       15.4                                                      20           19.2   18.4                                                      ______________________________________                                    

EXAMPLES 21-28

The examples are summarized in Table 2. Preparation of the foams wascarried out as in Example 1. Emulsifier according to Example 1 was used.The cement is a quick-setting cement (Fondue Lafarge). Abbreviationst_(R), t_(L) and t_(A) were explained in Examples 9-20.

Hard inorganic-organic foams in most cases with a regular cell structureand medium pore size were obtained. Test samples were taken from them todetermine the unit weight and compression strength after drying (3h/120° C.). The inorganic-organic foams obtained generally have goodmechanical properties and excellent fire characteristics. Since inaddition they have very good heat-insulating properties in the dry statethey are particularly suitable for use as constructional materials inthe building industry.

                                      TABLE 2                                     __________________________________________________________________________    Component I                          Component                                .THorizBrace.        Component II    III                                                      Tri- .THorizBrace.   .THorizBrace.                                            chloro-                                                                            Silicate        Organic              Com-                Polyisocyanate (g)                                                                         Ce-                                                                              fluoro-                                                                            comp.                                                                             Ce-                                                                              Triethyl-                                                                          Emul-                                                                             comp. C              pression               A 1                                                                              A 2                                                                              A 3 ment                                                                             methane                                                                            B 1 ment                                                                             amine                                                                              sifier Quant.                                                                            t.sub.R                                                                          t.sub.L                                                                          t.sub.A                                                                          Density                                                                            strength            Ex.                                                                              (g)                                                                              (g)                                                                              (g) (g)                                                                              (g)  (g) (g)                                                                              (g)  (g) Type                                                                             (g) (sec)                                                                            (sec)                                                                            (sec)                                                                            (kg/m.sup.3)                                                                       (kg/cm.sup.2)       __________________________________________________________________________    21 -- 200                                                                              --  -- 20   100 -- 2.5  0.2 C 8                                                                              50  20 31 43 104  5.8                 22 -- 200                                                                              --  -- 20   100 -- 2.5  0.4 C 8                                                                              50  20 30 41 175  5.2                 23 -- -- 200 -- 20   100 -- 2.5  0.2 C 8                                                                              50  20 30 38 166  12.2                24 -- -- 200 -- 20   100 -- 2.5  0.4 C 8                                                                              50  20 28 28 177  13.8                25 -- -- 200 50 20   100 50 2.0  0.4 C 8                                                                              50  20 32 46 220  15.4                26 -- -- 200 50 25   100 50 2.0  0.5 C 8                                                                              50  20 33 54 201  6.2                 27 -- -- 200 -- 25   100 100                                                                              2.0  0.5 C 8                                                                              50  20 34 57 151  4.2                 28 50 -- 150 -- 20   100 -- 2.0  0.2 C 13                                                                             50  20 26 35 114  5.2                 __________________________________________________________________________

EXAMPLES 29-35

100 g of polyisocyanate component A 1, 200 g of silicate component B 1and 5 g of an organic component C were vigorously mixed in a cardboardbeaker at room temperature with the aid of a high-speed stirrer for 15seconds. A pourable mass was obtained which was poured out into a can.The reaction mixture began to solidify after only a few minutes and thenhardened with evolution of heat within a short time.

A rock-hard but at the same time enormously elastic material wasobtained which was in no way brittle and macroscopically completelyhomogeneous and free from pores.

The solidification times depend on the nature and quantity of theorganic component C and on the ratio of silicate component to isocyanatecomponent.

The solidification times and the maximum mixing temperatures occurringare summarized in the following table for various organic components C.In the table,

t_(R) = stirring time

t_(A) = time until onset of solidification,

t_(S) = time after the mass can no longer be spread with a trowel,

t_(E) = time until complete hardening,

t_(max) = maximum temperature reached during the setting process

    ______________________________________                                                          t.sub.R                                                                              t.sub.A                                                                             t.sub.S                                                                             t.sub.E                                                                             t.sub.max                          Example                                                                              Component C                                                                              (sec)  (min) (min) (min) (° C)                       ______________________________________                                        29      C 12      15     5     8     18    107                                30     C 8        15     10    65    180   37                                 31      C 13      15     7     17    90    42                                 32     C 4        15     5     28    110   41                                 33     C 5        15     20    120   300   32                                 34     C 9        15     15    40    120   36                                 35      C 10      15     18    45    120   34                                 ______________________________________                                    

Although the invention has been described in detail in the foregoing forthe purposes of illustration, it is to be understood that such detail issolely for that purpose and that variations can be made therein by thoseskilled in the art without departing from the spirit and scope of theinvention except as it may be limited by the claims.

What is claimed is:
 1. A process for producing an inorganic-organicplastic with high strength, elasticity, dimensional stability underheat, and flame resistance, which is a composite material of apolymer/polysilicic acid gel, said composite being in the form of asolid/solid xerosol, said process comprising mixing and reacting:(A) anorganic polyisocyanate which is the phosgenation product of an anilineformaldehyde condensation, (B) a silica composition selected from thegroup consisting of:(i) an aqueous alkali metal silicate containingabout 20-70% by weight of said alkali metal silicate, (ii) an aqueoussilica sol having a solids content from 20 to 50%, and (iii) mixturesthereof, (C) an organic compound which contains(i) at least two hydrogenatoms capable of reacting with an isocyanate group, and (ii) at leastone non-ionic hydrophilic group, said non-ionic hydrophilic group beinga polyether group which contains at least 10% by weight ethylene oxidegroups, said mixing being carried out in such a way that eithercomponents (B) and (C) are mixed prior to mixing with (A), or components(A), (B) and (C) are mixed simultaneously, the mixing ratio of organiccontent to silicate content being between 70:30 to 20:80.
 2. The processof claim 1, wherein the quantity of the non-ionic hydrophilic groups ofcomponent (C) comprises 1-50% by weight based on component (A).
 3. Theprocess of claim 1, wherein compounds in addition to isocyanates whicheffect hardening of the water soluble silicates are included in themixture.
 4. The process of claim 1, wherein 0-50% by weight of an inertliquid boiling in the range of -25° to +80° C. is included in thereaction mixture as a blowing agent and the reaction proceeds withconcomitant foaming.
 5. The process of claim 1, wherein 0.001-10% byweight of activator is included in the reaction mixture.
 6. The processof claim 1, wherein 0-20% by weight of foam stabilizer is included inthe reaction mixture.
 7. The process of claim 1, wherein 0-20% by weightof emulsifying agent is included in the reaction mixture.
 8. The processof claim 1, wherein an inorganic or organic particulate or pulverulentmaterial is included in the reaction mixture.
 9. The process of claim 1,wherein said silica compound is an aqueous alkali metal silicate. 10.The product produced by the process of claim
 9. 11. The product of theprocess produced by claim 1.